C 1500 Suburban 2WD V8-5.7L VIN R (1996)
Compass: Initial Inspection and Diagnostic Overview
Circuit Operation
The Electrochromatic Rear View Mirror dims to a level required to minimize glare while still maintaining maximum rear vision.
The mirror switch has three positions; OFF, M and C/M. The M position energizes the mirror only while the C/M position energizes both the mirror and
the compass.
When a situation requires, the electronic module within the mirror assembly reduces the reflectivity of the Rear View Mirror and automatically dims the
LED compass readout. The Automatic Dimming function is inhibited while backing up.
COMPASS DISPLAY
The Compass Display circuitry is entirely contained within the Rearview Mirror.
The compass display is located on the mirror. It presents directional displays relative to symbolic horizon lines and road lines.
The electronic compass includes a fluxgate magnetic field sensor and a microprocessor. The microprocessor receives inputs from the sensor,
processes them and provides outputs to the compass display which indicates the vehicle heading, relative to the Earth's magnet fields.
Troubleshooting Hints
1. CHECK GAUGES Fuse 4. If fuse is open, LOCATE and REPAIR source of overload, and REPLACE Fuse.
2. CHECK that Ground G200 is clean and tight. CHECK for a broken (or partially broken) wire inside of the insulation which could cause system
malfunction but prove "GOOD" in Continuity/Voltage Check with a system disconnected. These Circuits may be intermittent or resistive when
loaded. and if possible, should be checked by monitoring for a Voltage drop with the system operational (under load).
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CHECK for proper installation of aftermarket electronic equipment which may affect the integrity of other system (Refer "Troubleshooting
Procedures"). See: Diagrams/Diagnostic Aids
